ADSL2+ speed query

I've had my ADSL2+ up for a week or so. With no devices or filter connected other than the modem (the supplied Huawei HG532d) I'm getting about 6 mbps download speed, which I gather is a bit slow. The TPG DSLAM map shows that I'm about ~950m line-of-sight, or ~1600m max. cable distance, from my exchange. Modem info is below. Can the speed be improved?

Yes, I've run the test at speedtest.telstra.com many times on a laptop with both an ethernet cable and Wifi and I get about the same result every time (6.1 to 6.4 mbps download). Time of day makes no difference (e.g. 4 am). Also with and without a filter+phone, no difference. I'll PM you that info.

I've checked and the number I gave is definitely the right number. It should have rung and taken a message if I had dipped out for a moment. I'm sorry I don't have another number at present. How about trying again tomorrow? I'll make sure the phone works in the meantime.

EDIT: It turns out the technician rang my home number and left a message. The number I gave wasn't my home number. I'll take it from here. Thanks.